Multi-modal magnetic imaging device and method based on fusion of NV color centers and MEMS atomic gas cell layer

Abstract

The application relates to a multi-modal magnetic imaging device and method based on the fusion of NV color centers and a MEMS atomic gas chamber layer. The device comprises: a composite sensing chip, which is sequentially integrated from bottom to top with an NV color center sensing layer, a spacing coupling layer and a MEMS atomic gas chamber layer; the NV color center sensing layer can detect a near-field magnetic signal to generate an NV fluorescence signal in an excited state; the spacing coupling layer can isolate and couple the near-field magnetic signal to the MEMS atomic gas chamber layer; the MEMS atomic gas chamber layer can detect a coupled magnetic signal to generate a magnetic response light signal in a SERF working state; and a processing system can enable the NV color center sensing layer to be in the excited state, enable the MEMS atomic gas chamber layer to be in the SERF working state, and generate a fusion magnetic image based on the two types of signals. The application can solve the problem that related technologies cannot realize efficient magnetic flux coupling between an NV color center sensing unit and an atomic magnetometer of the SERF at a chip level, and realize high-sensitivity and high-fineness magnetic imaging.

Description

Technical Field

[0001] This application relates to the field of magnetic imaging technology, and in particular to a multimodal magnetic imaging device and method based on the fusion of NV color centers and MEMS atomic gas cell layers. Background Technology

[0002] In the fields of quantum sensing and precision magnetic measurement, magnetic imaging technology based on diamond nitrogen-vacancy (NV) color centers utilizes the optically readable spin states of NV color centers for magnetic sensing, offering the advantage of high spatial resolution. Gas-cell atomic magnetometers based on spin-exchange relaxation-free (SERF) operation utilize the collective spin precession of alkali metal atoms in extremely weak magnetic fields for magnetic sensing, offering the advantage of high sensitivity. Combining the advantages of these two technologies to achieve magnetic imaging that combines high sensitivity with high spatial resolution is a key research focus.

[0003] Existing technologies physically juxtapose NV-center-based magnetic sensors with SERF-based atomic magnetometers, aiming to achieve high spatial resolution using NV-centers and high sensitivity using atomic magnetometers by simply combining two independent sensor modules. However, due to the physical separation between the two sensing modules and the mutual interference of optical, microwave, and magnetic environments, the magnetic signals generated by the sample cannot be efficiently coupled to the two simply superimposed sensing units.

[0004] There is currently no effective solution to the problem that it is impossible to achieve efficient magnetic flux coupling between the NV color center sensing unit and the SERF working state atomic magnetometer at the chip level in order to achieve magnetic imaging with both sensitivity and precision. Summary of the Invention

[0005] This application provides a multimodal magnetic imaging device and method based on the fusion of NV color centers and MEMS atomic gas cell layers, in order to solve the problem that related technologies cannot achieve efficient magnetic flux coupling between NV color center sensing units and atomic magnetometers in SERF working state at the chip level, so as to achieve magnetic imaging with both sensitivity and precision.

[0006] In a first aspect, this application provides a multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers, comprising:

[0007] The composite sensor chip integrates, from bottom to top, an NV color center sensing layer, a spacer coupling layer, and a MEMS atomic gas cell layer.

[0008] The NV color center sensing layer is used to detect the near-field magnetic signal generated by the sample under excitation state in order to generate NV fluorescence signal;

[0009] The spacer coupling layer is used to isolate the NV color center sensing layer and the MEMS atomic gas cell layer, couple the near-field magnetic signal into a coupled magnetic signal, and conduct it to the MEMS atomic gas cell layer.

[0010] The MEMS atomic gas cell layer is used to detect the coupled magnetic signal in the SERF operating state in order to generate a magneto-response optical signal;

[0011] The processing system operates on the composite sensor chip to put the NV color center sensing layer into the excited state, to put the MEMS atomic gas cell layer into the SERF working state, and to generate a fused magnetic image based on the NV fluorescence signal and the magneto-response optical signal.

[0012] In some of these embodiments, the first surface of the NV color center sensing layer is in contact with the second surface of the spacer coupling layer;

[0013] The NV color center sensing layer has an NV color center array; the distance between the NV color center array and the first surface of the NV color center sensing layer is less than a first preset threshold.

[0014] The spacer coupling layer is an insulating thermally conductive medium;

[0015] The MEMS atomic gas chamber layer is a sealed cavity, and an alkali metal atom source and a buffer gas are provided inside the MEMS atomic gas chamber layer.

[0016] In some further embodiments, the distance between the NV color center array and the first surface of the NV color center sensing layer is less than 100 nm;

[0017] The spacer coupling layer is made of silicon nitride or silicon dioxide and has a thickness of 50 nm to 10 μm.

[0018] The cavity planar dimensions of the MEMS atomic gas chamber layer range from 10 μm to 500 μm, and the height ranges from 1 μm to 50 μm.

[0019] The alkali metal atom source includes rubidium or potassium, and the buffer gas includes nitrogen or helium with a pressure range of 10 Torr to 1000 Torr.

[0020] In some further embodiments, the composite sensing chip further includes:

[0021] Integrated functional elements, disposed around the MEMS atomic gas chamber layer or embedded in the spaced coupling layer, are used to monitor and regulate the temperature of the MEMS atomic gas chamber layer and to apply a microwave field to the NV color center sensing layer.

[0022] In some embodiments, the processing system includes an optical subsystem; the optical subsystem includes:

[0023] A first laser is used to output a first wavelength laser, so that the first wavelength laser is incident on the NV color center sensing layer, so that the NV color center array in the NV color center sensing layer is in the excited state.

[0024] The second laser is used to output a second wavelength laser, which runs sequentially along the NV color center sensing layer and the spaced coupling layer, and is incident on the MEMS atomic gas cell layer to pump and probe the alkali metal atoms in the MEMS atomic gas cell layer, so that the MEMS atomic gas cell layer is in the SERF working state.

[0025] The spectrophotometer module is located near one end of the MEMS atomic gas cell layer. It is used to receive the mixed optical signal, separate the mixed optical signal into the NV fluorescence signal and the magnetic response optical signal, and guide them to the corresponding photodetectors respectively.

[0026] In some embodiments, the processing system includes a magnetic field subsystem; the magnetic field subsystem includes:

[0027] A three-dimensional coil array is arranged around the composite sensing chip to apply a compensating magnetic field to the entire composite sensing chip, to apply a near-zero magnetic field to the MEMS atomic gas cell layer, and to apply an adjustable bias magnetic field to the NV color center sensing layer. This allows the NV fluorescence signal generated by the NV color center sensing layer to carry the local magnetic field information of the sample under test, and the magnetoresistive optical signal generated by the MEMS atomic gas cell layer to carry the overall magnetic flux information of the sample under test.

[0028] In some further embodiments, the magnetic field subsystem further includes:

[0029] A programmable microwave source, comprising at least an independent first channel and a second channel;

[0030] The first channel is connected to a microwave antenna integrated in the composite sensor chip via a microwave transmission line to generate a first tunable microwave field to drive electron spin resonance in the NV color center sensing layer.

[0031] The second channel, connected to the three-dimensional coil group, is used to generate an adjustable radio frequency or a second adjustable microwave field to modulate the atomic spins within the MEMS atomic gas chamber layer;

[0032] A magnetic shielding cylinder is placed outside the three-dimensional coil group to attenuate the environmental interference magnetic field.

[0033] In some embodiments, the processing system further includes a signal processing subsystem;

[0034] The signal processing subsystem is used to perform magnetic scanning on the sample under test based on the magnetic response optical signal generated by the MEMS atomic gas cell layer to identify the region of interest; the signal processing subsystem is also used to spatially guide the scanning imaging area of ​​the NV color center sensing layer based on the identification result of the region of interest to determine the scanning area of ​​the NV color center sensing layer.

[0035] The signal processing subsystem is also used to generate control commands within the scanning area to perform traversal scanning excitation of the scanning points of the NV color center sensing layer, and to simultaneously acquire the NV fluorescence signal generated at each scanning point and the magneto-response optical signal generated at the location of the MEMS atomic gas cell layer corresponding to each scanning point.

[0036] The signal processing subsystem is also used to perform real-time in-situ calibration of the relative magnetic field change measured by the NV fluorescence signal based on the absolute magnetic field value measured by the magneto-response optical signal, establish a calibration model, and perform calibration on the relative magnetic field change based on the calibration model.

[0037] In some further embodiments, the signal processing subsystem is also used to establish a physical forward model describing the composite sensing chip, the physical forward model including the Green's function of the NV color center sensing layer, the weighting function of the MEMS atomic air cell layer, and the magnetic flux coupling relationship between the NV color center sensing layer and the MEMS atomic air cell layer through the spacer coupling layer.

[0038] The signal processing subsystem is also used to perform a collaborative inversion of the synchronously acquired NV fluorescence signal and magnetic response optical signal based on the physical forward model, calculate the magnetic moment distribution of the sample under test, and generate the fused magnetic image based on the magnetic moment distribution.

[0039] Secondly, this application provides a multimodal magnetic imaging method based on the fusion of NV color centers and MEMS atomic gas cell layers, including:

[0040] A composite sensing chip, which integrates an NV color center sensing layer, a spacer coupling layer, and a MEMS atomic gas cell layer from bottom to top, was used to scan the sample under test.

[0041] The NV fluorescence signal generated by the NV color center sensing layer in the composite sensing chip and the magneto-response optical signal generated by the MEMS atomic gas cell layer in the composite sensing chip are obtained.

[0042] A fused magnetic image is generated based on the NV fluorescence signal and the magneto-response optical signal.

[0043] Compared with the prior art, the embodiments of this application have the following beneficial effects:

[0044] In this embodiment, a composite sensing chip is used to sequentially integrate an NV color center sensing layer, a spacer coupling layer, and a MEMS atomic gas cell layer from bottom to top. The NV color center sensing layer, in an excited state, detects the near-field magnetic signal generated by the sample to generate an NV fluorescence signal. The spacer coupling layer isolates the two layers and couples the near-field magnetic signal into a coupled magnetic signal, which is then transmitted to the MEMS atomic gas cell layer. The MEMS atomic gas cell layer, in SERF operating state, detects the coupled magnetic signal to generate a magnetoresistive optical signal. The processing system excites the NV color center sensing layer and puts the MEMS atomic gas cell layer into SERF operating state, generating a fused magnetic image based on the NV fluorescence signal and the magnetoresistive optical signal. Thus, at the chip level, the physical fusion and magnetic flux coupling of NV color center high spatial resolution detection and SERF atomic magnetometer high sensitivity detection are realized. This allows the near-field magnetic signal generated by the sample to be efficiently transmitted to the MEMS atomic gas cell layer through the spacer coupling layer, avoiding the problems of low signal coupling efficiency and environmental interference caused by the physical separation of the two sensing modules in the prior art. At the same time, the processing system performs joint processing on the two types of signals, enabling the high spatial resolution information and high sensitivity information to be synergistically fused. The generated fused magnetic image has both high spatial resolution and high sensitivity, solving the technical problem that the prior art cannot synergistically leverage the combined advantages of the two sensors.

[0045] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0046] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0047] Figure 1 This is a structural diagram of a composite sensor chip provided in an embodiment of this application;

[0048] Figure 2 This is a structural diagram of a multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers according to an embodiment of this application;

[0049] Figure 3 This is a flowchart of laser transmission provided in one embodiment of this application;

[0050] Figure 4 This is a flowchart of a multimodal magnetic imaging method based on the fusion of NV color centers and MEMS atomic gas cell layers provided in an embodiment of this application;

[0051] Figure 5 This is a flowchart illustrating a specific process for a multimodal magnetic imaging method based on the fusion of NV color centers and MEMS atomic gas cell layers, provided in one embodiment of this application.

[0052] In the diagram: 1. Composite sensor chip; 2. NV color center sensing layer; 3. Spacing coupling layer; 4. MEMS atomic gas cell layer; 5. Magnetic field subsystem; 6. Signal processing subsystem; 7. Second laser; 8. First laser; 9. Three-dimensional coil group; 10. Programmable microwave source; 11. Microwave antenna layer; 12. Integrated functional element; 13. Acousto-optic modulator; 14. First long-pass dichroic mirror; 15. Second long-pass dichroic mirror; 16. Objective lens; 17. Bandpass filter; 18. CMOS camera; 19. First lens; 20. Second lens; 21. Wollaston prism; 22. Differential photodetector; 23. Optical subsystem. Detailed Implementation

[0053] To better understand the purpose, technical solution, and advantages of this application, the application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0054] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these” used in this application do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to these processes, methods, products, or devices. Words such as “connected,” “linked,” and “coupled” used in this application are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. Normally, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," "third," etc., used in this application are merely to distinguish similar objects and do not represent a specific order.

[0055] This embodiment provides a multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers. Figure 1 A structural diagram of the composite sensor chip provided for this embodiment. Figure 2 For a structural diagram of the multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers provided in this embodiment, please refer to... Figure 1 and Figure 2 The device includes a composite sensor chip 1 and a processing system that acts on the composite sensor chip 1.

[0056] The composite sensor chip 1 integrates, from bottom to top, an NV color center sensing layer 2, a spacer coupling layer 3, and a micro-electro-mechanical systems (MEMS) atomic cell layer. The MEMS atomic cell layer will be referred to as the MEMS atomic cell layer 4 from this point onward. The NV color center sensing layer 2 is used to detect the near-field magnetic signal generated by the sample under excitation to generate an NV fluorescence signal. The spacer coupling layer 3 isolates the NV color center sensing layer 2 and the MEMS atomic cell layer 4, coupling the near-field magnetic signal into a coupled magnetic signal, which is then conducted to the MEMS atomic cell layer 4. The MEMS atomic cell layer 4 is used to detect the coupled magnetic signal under SERF operating conditions to generate a magnetoresistive optical signal.

[0057] In actual operation, the sample under test can be directly supported on the lower surface of the NV color center sensing layer 2, i.e., the side away from the spacer coupling layer 3, or cultured on this surface. This allows the near-field magnetic signal generated by the sample to be coupled to the NV color center array via the shortest path, minimizing signal attenuation and distortion during spatial propagation. The near-field magnetic signal generated by the sample under test first acts on the NV color center sensing layer 2. In the excited state, the NV color center sensing layer 2 detects the near-field magnetic signal and generates an NV fluorescence signal. Simultaneously, this near-field magnetic signal is coupled into a coupled magnetic signal via the spacer coupling layer 3, and then efficiently conducted to the MEMS atomic gas cell layer 4 through the spacer coupling layer 3. In the SERF operating state, the MEMS atomic gas cell layer 4 detects the coupled magnetic signal and generates a magnetoresistive optical signal. Based on the above structure, the NV color center sensing layer 2 and the MEMS atomic gas cell layer 4 achieve tight integration and magnetic flux coupling at the chip level, avoiding the signal loss and environmental interference problems of traditional discrete arrangements.

[0058] The processing system is used to excite the NV color center sensing layer 2, to put the MEMS atomic gas cell layer 4 into SERF working state, and to generate a fused magnetic image based on the NV fluorescence signal and the magneto-response optical signal.

[0059] In view of this, this embodiment uses the three-layer integrated structure of the composite sensing chip 1 to enable the high spatial resolution detection of the NV color center and the high sensitivity detection of the SERF atomic magnetometer composed of the MEMS atomic gas cell layer 4 to work together on the same chip, and the two types of signals are jointly processed by the processing system to generate a fused magnetic image.

[0060] In this embodiment, the composite sensing chip features a three-layer structure, sequentially integrated from bottom to top along the thickness direction: an NV color center sensing layer, a spacer coupling layer, and a MEMS atomic gas cell layer. The spacer coupling layer couples the near-field magnetic signal detected by the NV color center sensing layer into a coupled magnetic signal, which is then transmitted to the MEMS atomic gas cell layer. This achieves chip-level physical fusion and magnetic flux coupling of the two quantum sensors. This structure allows the near-field magnetic signal generated by the sample to be transmitted to the MEMS atomic gas cell layer with minimal attenuation and distortion, avoiding the problems of low signal coupling efficiency and environmental interference in traditional discrete arrangements. Simultaneously, the processing system keeps the NV color center sensing layer in an excited state and the MEMS atomic gas cell layer in a SERF working state. Based on the NV fluorescence signal and the magnetoresistance optical signal, joint processing is performed to synergistically fuse high spatial resolution information with high sensitivity information, generating a fused magnetic image that possesses both nanometer-level spatial resolution and femtotes-level sensitivity. Based on the above technical effects, this embodiment solves the problem that related technologies cannot achieve efficient magnetic flux coupling between the NV color center sensing unit and the SERF atomic magnetometer at the chip level, thus making it difficult to balance imaging sensitivity and spatial resolution.

[0061] In some embodiments, the first surface of the NV center sensing layer is in contact with the second surface of the spacer coupling layer. The NV center sensing layer contains an NV center array, and the distance between the NV center array and the first surface of the NV center sensing layer is less than a first preset threshold. Therefore, the NV center array can sense the magnetic signal generated by the sample under test at high resolution using near-field detection, avoiding signal attenuation and spatial resolution degradation during detection. Simultaneously, because the NV center array is adjacent to the spacer coupling layer, the near-field magnetic signal it detects can be transmitted to the spacer coupling layer via the shortest path, reducing signal loss during interlayer transmission.

[0062] The spacer coupling layer is an insulating and thermally conductive medium. Therefore, it physically isolates the NV color center sensing layer from the MEMS atomic cell layer, preventing electrical crosstalk and spin coherence interference between the two during operation. Simultaneously, its thermal conductivity rapidly dissipates the high heat generated by the MEMS atomic cell layer, maintaining the NV color center sensing layer at a normal operating temperature. Furthermore, as a low-magnetic-noise insulating medium, the spacer coupling layer itself does not introduce additional magnetic interference, maintaining the fidelity of the near-field magnetic signal during transmission.

[0063] The MEMS atomic gas chamber layer is a sealed cavity containing an alkali metal atom source and a buffer gas. Therefore, the sealed cavity provides a stable working environment for the alkali metal atoms, enabling them to form high-density atomic vapor under heating conditions. The buffer gas suppresses collisional relaxation between the alkali metal atoms and the cavity wall, extending the coherence time of the atomic spins, thus supporting the establishment of the SERF operating state. This constitutes an atomic magnetometer based on the spin-free exchange relaxation effect, used to detect coupled magnetic signals with femtoslas-level sensitivity and generate magnetoresistance optical signals. In SERF operating mode, the alkali metal atoms within the MEMS atomic gas chamber layer exhibit extremely high sensitivity to weak magnetic fields, enabling the detection of coupled magnetic signals conducted through the spacer coupling layer.

[0064] Given the above structure, the composite sensing chip exhibits a complete signal transmission chain when operating in the adapted working environment provided by the processing system. Specifically, the near-field magnetic signal generated by the sample under test is first sensed by the NV color center sensing layer with high spatial resolution and generates an NV fluorescence signal. This near-field magnetic signal is simultaneously coupled into a coupled magnetic signal via a spacer coupling layer and transmitted to the MEMS atomic gas cell layer with minimal attenuation and distortion. In SERF mode, the MEMS atomic gas cell layer detects this coupled magnetic signal with high sensitivity and generates a magnetoresistive optical signal. The NV fluorescence signal carries the local high-resolution magnetic field information of the sample under test, while the magnetoresistive optical signal carries the overall magnetic flux information of the sample. Both types of signals are simultaneously acquired at the chip level and transmitted to the processing system for joint processing, ultimately generating a fused magnetic image with both nanometer-level spatial resolution and femtotes-level sensitivity.

[0065] In the specific fabrication process, heterogeneous integration is achieved between the NV color center sensing layer and the spacer coupling layer, and between the spacer coupling layer and the MEMS atomic gas chamber layer, through van der Waals bonding or epoxy resin bonding. This bonding method ensures close contact between the layers while avoiding damage to the NV color centers and alkali metal atoms caused by high-temperature processes, thus ensuring the overall structural stability and functionality of the chip.

[0066] In some further embodiments, the parameter design of the composite sensing chip includes:

[0067] The distance between the NV center array and the first surface of the NV center sensing layer is less than 100 nm, which puts the NV center array in the near-field detection region, enabling it to sense the surface micro-magnetic distribution of the sample under test with nanometer-level spatial resolution. This distance range ensures that the NV center spins maximize the response intensity to the sample's magnetic field.

[0068] The spacer coupling layer is made of silicon nitride or silicon dioxide, with a thickness ranging from 50 nm to 10 μm. This allows the spacer coupling layer to physically completely isolate the NV color center sensing layer from the MEMS atomic gas cell layer, avoiding electrical crosstalk and spin decoherence. Simultaneously, this thickness range matches the characteristic attenuation length of the NV color center near-field detection, ensuring that the near-field magnetic signal can penetrate the spacer coupling layer with minimal distortion and attenuation, while providing sufficient structural support and thermal isolation buffer for the MEMS fabrication of the upper MEMS atomic gas cell layer. For example, a spacer coupling layer thickness of 50 nm is suitable for high-fidelity transmission of high-frequency magnetic signals; 5 μm is suitable for high-temperature SERF operating scenarios requiring stronger thermal isolation; and 10 μm is suitable for the structural support requirements of large-size MEMS atomic gas cell layers.

[0069] The thickness of the spacing coupling layer is also related to the frequency characteristics of the magnetic signal being measured. For high-frequency magnetic signals, a thinner spacing coupling layer (e.g., 50nm to 100nm) helps reduce eddy current losses and phase delay; for quasi-static magnetic signals, the thickness can be appropriately increased to enhance structural support and thermal isolation. This matching relationship between thickness and frequency allows the composite sensing chip to adapt to the magnetic imaging requirements of different application scenarios.

[0070] The MEMS atomic gas cell layer has a cavity planar size of 10 μm to 500 μm and a height of 1 μm to 50 μm. This allows the MEMS atomic gas cell layer to form small-sized atomic gas cells suitable for SERF operation while maintaining MEMS process compatibility. The smaller cavity size limits the diffusion range of alkali metal atoms, increasing the spatial localization of the atomic ensemble and thus improving the spatial resolution of the atomic magnetometer. Simultaneously, this size range matches the thickness of the spacer coupling layer, ensuring that the coupling magnetic flux conducted from the lower layer can effectively cover the entire gas cell region, exciting the collective response of atomic spins. For example, a cavity planar size of 10 μm and a height of 1 μm is suitable for microscopic magnetic imaging requiring the highest spatial resolution; 250 μm × 25 μm is suitable for general scenarios balancing sensitivity and resolution; and 500 μm × 50 μm is suitable for weak magnetic detection scenarios requiring maximum sensitivity.

[0071] The alkali metal atom source includes rubidium or potassium, and the buffer gas includes nitrogen or helium, with a pressure range of 10 Torr to 1000 Torr. This allows the formation of suitable atomic number density and spin relaxation suppression conditions within the MEMS atomic gas chamber layer for SERF operation. Specifically, rubidium or potassium atoms generate sufficiently dense atomic vapor under heating conditions, providing a spin carrier for high-sensitivity magnetic detection; nitrogen or helium, as a buffer gas, effectively suppresses collisional relaxation between alkali metal atoms and the chamber wall, extending the coherence time of atomic spins. The pressure range of 10 Torr to 1000 Torr covers a broad spectrum of conditions from low pressure to near atmospheric pressure, and can be adjusted according to specific operating temperature and sensitivity requirements. For example, a pressure of 10 Torr is suitable for low-noise detection at low operating temperatures; 500 Torr is suitable for SERF operating points near room temperature; and 1000 Torr is suitable for high-temperature operating scenarios requiring strong collision suppression.

[0072] The parameters mentioned above are not completely independent couplings, but can be collaboratively optimized according to specific application scenarios. For example, the thickness of the spacer coupling layer and the depth of the NV color center jointly determine the transmission efficiency of the near-field magnetic signal; the size of the MEMS gas chamber layer and the internal gas pressure jointly determine the spatial resolution and sensitivity bandwidth of the atomic magnetometer; and these parameters collectively affect the overall performance of the composite sensor chip. In specific combinations of values, as long as each parameter is within the above-mentioned range, the basic fusion function of the NV color center and the SERF atomic magnetometer can be achieved; and through further collaborative optimization, an optimal balance can be achieved between indicators such as sensitivity, spatial resolution, and operating temperature under specific scenarios.

[0073] In some further embodiments, please continue to refer to Figure 1The composite sensor chip 1 also includes an integrated functional element 12. This integrated functional element 12 is disposed around the MEMS atomic gas chamber layer 4 or embedded in the spacer coupling layer 3, and is used to monitor and regulate the temperature of the MEMS atomic gas chamber layer 4, and also to apply a microwave field to the NV color center sensing layer 2.

[0074] In some further embodiments, the integrated functional elements include a micro heater, a temperature sensor, and a microwave antenna.

[0075] A micro-heater is positioned around the MEMS atomic cell layer to heat it, bringing the alkali metal atoms inside to the temperature required for SERF operation. Due to the small size and low heat capacity of the MEMS atomic cell layer, the micro-heater enables rapid heating and precise temperature control, while avoiding thermal interference with the underlying NV color center sensing layer.

[0076] Temperature sensors are also positioned around the MEMS atomic cell layer or embedded in the spacer coupling layer to monitor the temperature of the MEMS atomic cell layer in real time and feed the temperature data back to the processing system. The processing system then controls the output power of the micro-heater to maintain the stable operating temperature of the MEMS atomic cell layer. The placement of the temperature sensors enables closed-loop control of the temperature of the MEMS atomic cell layer, ensuring the long-term stability of the alkali metal atom number density and the SERF operating state.

[0077] The microwave antenna is integrated within the composite sensor chip, specifically positioned within the spaced coupling layer or around the NV color center sensing layer. It receives microwave signals from a programmable microwave source and applies a frequency-tunable microwave field to the NV color center array within the NV color center sensing layer to drive the electron spin resonance of the NV color centers. Integrating the microwave antenna within the chip significantly shortens the coupling distance between the microwave field and the NV color centers, improves microwave excitation efficiency, and reduces power consumption and thermal effects.

[0078] In some further embodiments, please continue to refer to Figure 1 The bottom layer of the composite sensor chip 1 also has an independently disposed microwave antenna layer 11. Located below the NV color center sensing layer 2, the microwave antenna layer 11 is formed into a coplanar waveguide or microstrip line structure through photolithography or deposition processes, and is used to apply a uniform and efficient microwave field to the NV color center sensing layer 2. By independently disposing of the microwave antenna layer 11 at the bottom layer of the chip, functional interference with the layers above is avoided, while simultaneously ensuring that the microwave field uniformly covers the entire NV color center array from bottom to top, improving the efficiency and uniformity of microwave excitation.

[0079] In some of these embodiments, please continue to refer to Figure 2 The processing system includes an optical subsystem 23; the optical subsystem 23 includes a first laser 8, a second laser 7, and a beam splitting detection module.

[0080] The first laser 8 outputs a first wavelength laser light, which is then incident on the NV color center sensing layer 2 to excite the NV color center array within the NV color center sensing layer 2. Specifically, the first wavelength laser is typically selected as 532nm green light, which matches the optical absorption peak of the NV color centers and can efficiently excite the electron spins of the NV color centers from the ground state to the excited state. During the de-excitation process, the excited state emits an NV fluorescence signal in the red light band. The incident direction of the first wavelength laser is consistent with the thickness direction of the composite sensing chip 1, ensuring that the laser can penetrate vertically into the NV color center sensing layer 2 and uniformly excite the entire NV color center array region.

[0081] The second laser 7 outputs a second wavelength laser, which sequentially travels along the NV color center sensing layer 2 and the spacer coupling layer 3, incident on the MEMS atomic gas chamber layer 4 to pump and probe the alkali metal atoms within it, thus putting the MEMS atomic gas chamber layer 4 into SERF operating mode. Specifically, the second wavelength laser is typically selected to resonate with the D1 or D2 lines of the alkali metal atoms; for example, 795 nm or 780 nm is used for rubidium atoms. During the pumping process, this laser polarizes the spins of the alkali metal atoms along the optical axis, forming macroscopic spin polarization. During the detection process, the linearly polarized probe light, after passing through the gas chamber, will have its polarization plane rotate due to the precession of the atomic spins under the influence of the magnetic field; this rotation angle is proportional to the magnetic field strength. When the second wavelength laser passes through the NV color center sensing layer 2 and the spacer coupling layer 3 in sequence along the thickness direction, the laser can reach the MEMS atomic gas cell layer 4 without damage because these two layers have high transmittance to the selected wavelength. At the same time, the NV color center sensing layer 2 does not resonate and absorb the laser of this wavelength, thus avoiding optical crosstalk.

[0082] The spectrophotometer module, located near one end of the MEMS atomic gas cell layer 4, receives the mixed optical signal and separates it into an NV fluorescence signal and a magnetoresistive optical signal, which are then directed to their respective photodetectors. The spectrophotometer module separates the mixed optical signal based on wavelength differences: the NV fluorescence signal is located in the red light band, approximately 600nm to 800nm, while the magnetoresistive optical signal is located in the near-infrared band, the same as or similar to the second wavelength of the laser. By using a combination of dichroic mirrors or bandpass filters, the spectrophotometer module can efficiently separate the two types of signals and send them to high-sensitivity photodetectors for photoelectric conversion.

[0083] In actual operation, the complete optical path formed by the optical subsystem includes: a first-wavelength laser output from a first laser is incident on the composite sensing chip along the thickness direction, penetrating vertically to the NV color center sensing layer, exciting the NV color center array to generate NV fluorescence signals; simultaneously, a second-wavelength laser output from a second laser also passes sequentially through the NV color center sensing layer and the spacer coupling layer along the thickness direction, incident on the MEMS atomic gas cell layer, pumping and probing alkali metal atoms, and carrying atomic spin precession information through the gas cell; the two types of optical signals are mixed on the light-emitting side of the composite sensing chip, received and separated by the beam splitting detection module, and finally converted into electrical signals and sent to the processing system for subsequent processing. The entire optical path is transmitted vertically along the chip thickness direction, realizing coaxial confocal excitation and detection of the same detection area, ensuring that the NV fluorescence signal and the magnetoresistive optical signal originate from the same spatial location.

[0084] In some further embodiments, please continue to refer to Figure 1 and Figure 2 The MEMS atomic gas chamber layer 4 is equipped with an optical window made of a transparent material, such as glass or quartz. This window allows the second wavelength laser output from the second laser 7 to enter the gas chamber to pump and probe alkali metal atoms, while simultaneously allowing the probe light carrying atomic spin information to pass through the gas chamber and be collected by the optical subsystem 23. The optical window ensures efficient transmission of the optical signal within the gas chamber layer, avoiding the problem of the optical path being blocked by the sealed cavity.

[0085] In some further embodiments, the optical subsystem also includes a beam combining element disposed on the light-emitting side of the first laser and the second laser, for combining the first wavelength laser and the second wavelength laser into the same main optical path to form a combined laser beam.

[0086] In some further embodiments, please continue to refer to Figure 2 The beam combining element includes a first long-pass dichroic mirror 14, a second long-pass dichroic mirror 15, or a fiber optic combiner. The coating characteristics of the first long-pass dichroic mirror 14 and the second long-pass dichroic mirror 15 are designed to provide high reflectivity for the first wavelength laser (532nm) output from the first laser 8 and high transmittance for the second wavelength laser (795nm) output from the second laser 7, ensuring that the two laser beams overlap spatially and propagate in the same direction. When using a fiber optic combiner, the two laser beams are input into two separate optical fibers and combined into a single beam output from a single fiber. The beam combining element ensures that the dual-wavelength lasers can be incident on the composite sensor chip 1 along identical optical paths, achieving coaxial excitation of the same detection area and ensuring spatial consistency between the two types of signals.

[0087] In some further embodiments, please continue to refer to Figure 2The optical subsystem 23 also includes a beam-expanding and collimating lens group, located on the output side of the beam-combining element, for expanding and collimating the combined laser beam. The beam-expanding and collimating lens group typically consists of a first lens 19 and a second lens 20. By adjusting the lens spacing, the laser beam diameter is expanded to several millimeters, while simultaneously eliminating beam divergence. The expanded laser beam can more fully fill the rear aperture of the subsequent objective lens 16, improving the quality of the focused spot and energy utilization; the collimated parallel beam ensures that the laser maintains a stable beam diameter and direction during transmission, reducing the complexity of optical path adjustment.

[0088] In some further embodiments, please continue to refer to Figure 2 The optical subsystem 23 also includes an acousto-optic modulator 13, which is positioned on the light-emitting side of the first laser 8 or before the beam-combining element, for intensity modulation or pulse control of the first wavelength laser. The acousto-optic modulator 13 achieves rapid switching, intensity adjustment, or frequency shifting of the laser through the interaction between the ultrasonic field and the laser, thereby optimizing the excitation efficiency of the NV color center or realizing a pulse excitation scheme with precise timing control.

[0089] In some further embodiments, the optical subsystem also includes a scanning galvanometer, disposed on the light-emitting side of the beam-expanding collimating lens group, for controlling the scanning position of the combined laser beam on the surface of the composite sensor chip. The scanning galvanometer consists of two orthogonally arranged rotating mirrors. By controlling the deflection angle of the mirrors, the laser beam performs a two-dimensional scan on the chip surface. The scanning galvanometer is electrically connected to the processing system, which generates control signals based on a preset scanning path or a real-time identified region of interest, driving the scanning galvanometer to achieve rapid and precise beam deflection, thereby realizing point-by-point scanning imaging of the sample area.

[0090] In some further embodiments, please continue to refer to Figure 2 The optical subsystem 23 also includes a first lens 19 and a second lens 20, which are disposed on the light-emitting side of the scanning galvanometer and are used to convert the scanned laser into a telecentric scanning light field. The first lens 19 is an f-theta lens, which ensures that the laser beam is focused on the same focal plane at different scanning angles and that the focal point position is linearly related to the scanning angle. The second lens 20 works in conjunction with the first lens 19 to convert the angular deflection of the scanning galvanometer into a parallel beam displacement on the rear focal plane of the objective lens 16, thereby achieving linear scanning on the focal plane of the objective lens 16.

[0091] In some further embodiments, please continue to refer to Figure 2 The optical subsystem 23 also includes multiple mirrors and aperture stops, which are positioned appropriately in the optical path. The mirrors are used to change the direction of beam transmission or fold the optical path to reduce the system size; the aperture stops are located at the back focal plane or intermediate image plane of the objective lens 16 to limit the beam diameter, eliminate stray light, and improve imaging contrast.

[0092] In some further embodiments, please continue to refer to Figure 2 The spectroscopic detection module includes a bandpass filter 17, a Wollaston prism 21, and a differential photodetector 22. The bandpass filter 17, with a passband of 700±20 nm, is positioned in the NV fluorescence signal path to selectively transmit the NV fluorescence signal and block stray light. The Wollaston prism 21, positioned in the magneto-response optical signal path, decomposes the linearly polarized probe light into two beams with orthogonal polarization directions. The differential photodetector 22, positioned on the output side of the Wollaston prism 21, receives the two orthogonally polarized beams and outputs a differential signal. This differential signal is proportional to the polarization rotation angle caused by atomic spin precession, thereby significantly improving the detection sensitivity and common-mode noise suppression capability of the magneto-response optical signal.

[0093] In some further embodiments, please continue to refer to Figure 2 The optical subsystem 23 also includes a complementary metal-oxide-semiconductor (CMOS) camera, hereinafter referred to as CMOS camera 18, which is located after the spectrophotometer or on a separate optical path branch and is used for wide-field imaging or assisting focusing of the sample under test. CMOS camera 18 can observe the sample position and chip surface state in real time, which facilitates the operator to perform sample alignment and focus adjustment. It can also be used to quickly preview the morphology and structure of the sample and provide a spatial reference for subsequent magnetic imaging.

[0094] The embodiments and specific implementations of the aforementioned optical subsystem are described below. Figure 3 This is a flowchart of the laser transmission process provided in this embodiment. Please refer to it. Figure 3 The laser transmission process in the optical subsystem corresponding to the complete optical path is as follows:

[0095] The first wavelength laser output from the first laser and the second wavelength laser output from the second laser are combined into a single laser beam by a beam-combining element. This combined laser beam is then expanded and collimated by a beam-expanding and collimating lens group before being incident on a scanning galvanometer. The scanning galvanometer deflects according to a control signal from the processing system, causing the laser beam to exit at different angles. The emitted laser beam passes sequentially through a scanning lens and a tube lens, converting it into a telecentric scanning light field before being incident on a corresponding dichroic mirror. The dichroic mirror reflects the excitation light into the objective lens. The objective lens focuses the laser beam onto the same detection area of ​​the composite sensor chip.

[0096] The focused laser passes sequentially through the MEMS atomic gas cell layer and the spacer coupling layer along the chip thickness direction to reach the NV color center sensing layer, exciting the NV color center array to generate NV fluorescence signals. At the same time, the second wavelength laser pumps and probes the alkali metal atoms in the MEMS atomic gas cell layer as it passes through, and the probe light carrying atomic spin information is transmitted out of the chip.

[0097] The NV fluorescence signal and the transmitted magnetic response light signal returned from the chip return along the original optical path, are collected by the objective lens, transmitted through the dichroic mirror, and then enter the spectrophotometer. The spectrophotometer separates the mixed light signal into the NV fluorescence signal and the magnetic response light signal according to the wavelength difference, and directs them to the corresponding photodetectors to be converted into electrical signals, which are then sent to the processing system for further processing.

[0098] In some of these embodiments, please continue to refer to Figure 1 and Figure 2 The processing system includes a magnetic field subsystem 5; the magnetic field subsystem 5 includes a three-dimensional coil group 9. The three-dimensional coil group 9 is arranged around the composite sensing chip 1 and is used to apply a compensation magnetic field to the composite sensing chip 1 as a whole, to apply a near-zero magnetic field to the MEMS atomic gas cell layer 4, and to apply an adjustable bias magnetic field to the NV color center sensing layer 2, so that the NV fluorescence signal generated by the NV color center sensing layer 2 carries the local magnetic field information of the sample under test, and the magnetoresistive optical signal generated by the MEMS atomic gas cell layer 4 carries the overall magnetic flux information of the sample under test.

[0099] Specifically, the three-dimensional coil assembly consists of three pairs of orthogonally placed Helmholtz coils, which generate uniform magnetic fields in the X, Y, and Z directions, respectively. It is positioned around the composite sensor chip, placing the chip in the central uniform magnetic field region of the coil assembly.

[0100] The compensation magnetic field is used to counteract the Earth's magnetic field and stray magnetic fields in the environment. Since the MEMS atomic gas cell layer requires a near-zero magnetic field environment with a total field strength of less than 1 nT to enter SERF operating mode, the three-dimensional coil assembly first applies a compensation magnetic field of equal magnitude but opposite direction to the external magnetic field to cancel the background magnetic field in the chip's location to near-zero levels. The application of the compensation magnetic field is a dynamic closed-loop process: the processing system reads the magnetic response signal from a high-precision magnetic sensor or the MEMS atomic gas cell layer itself, calculates the residual magnetic field component in real time, and drives the three-dimensional coil assembly to perform fine adjustments until the residual magnetic field meets the SERF operating conditions.

[0101] Near-zero magnetic field specifically refers to the working environment constructed for the MEMS atomic gas cell layer. After the compensating magnetic field cancels out the background magnetic field, the three-dimensional coil group further maintains the magnetic field strength in this region below 1 nT, providing the necessary conditions for the spin-free exchange relaxation state of alkali metal atoms. In the near-zero magnetic field environment, the exchange collisions between the spins of alkali metal atoms no longer lead to spin relaxation, and the coherence time of the atomic spins is greatly extended, thus enabling the atomic magnetometer to reach the femtotes level of limiting sensitivity. At this time, even if the coupled magnetic signal transmitted through the spacer coupling layer is extremely weak, it can induce detectable precession of atomic spin polarization, and this precession information is encoded in the transmitted magneto-response optical signal. Since the MEMS atomic gas cell layer has a certain volume, its response is sensitive to the average magnetic field within the gas cell area; therefore, the magneto-response optical signal carries the overall magnetic flux information of the sample under test.

[0102] The adjustable bias magnetic field is specifically designed for quantum state manipulation of the NV center sensing layer. The electron spins of the NV centers undergo Zeeman splitting in the magnetic field, with the splitting interval proportional to the magnetic field strength. The magnitude of the magnetic field can be inferred by measuring the splitting frequency. A three-dimensional coil array applies a precisely controllable bias magnetic field in both magnitude and direction, superimposing the magnetic field of the sample to be measured onto this bias magnetic field, based on the compensating magnetic field. The introduction of the bias magnetic field serves two purposes: first, it shifts the magnetic field to be measured from near zero field to the linear response region of the NV center optically detected magnetic resonance (ODMR) spectrum, improving measurement sensitivity; second, by changing the direction of the bias magnetic field, selective measurement of the sample's magnetic field vector components can be achieved. Because the NV center array is located near the surface and spatially localized, its response is extremely sensitive to the microscopic magnetic distribution of the sample surface. Therefore, the NV fluorescence signal carries local high-resolution magnetic field information of the sample under test.

[0103] In this embodiment, a compensating magnetic field, a near-zero magnetic field, and a bias magnetic field are applied synergistically within the three-dimensional coil array: the compensating magnetic field serves as the base layer, providing a clean magnetic environment for the entire chip; the near-zero magnetic field serves as the operating condition for the MEMS atomic gas cell layer, ensuring its high-sensitivity detection capability; and the bias magnetic field serves as the manipulation mechanism for the NV color center sensing layer, enabling it to quantitatively measure the local magnetic field. The combined effect of these three magnetic fields allows the NV fluorescence signal and the magnetoresistive optical signal to carry the local magnetic field information and overall magnetic flux information of the sample under test, respectively, providing a physical basis for the subsequent coordinated processing of these two types of signals.

[0104] In some further embodiments, the three-dimensional coil assembly is an integrated design, comprising three pairs of orthogonal coils nested and integrated on the same skeleton structure, with the composite sensing chip located in the common central region of the three pairs of coils. This structure ensures the relative positional accuracy between the coils, effectively reducing the impact of assembly errors on magnetic field uniformity.

[0105] In some further embodiments, please continue to refer to Figure 2 The magnetic field subsystem 5 also includes a programmable microwave source 10 and a magnetic shielding cylinder. The programmable microwave source 10 includes at least a separate first channel and a second channel.

[0106] Specifically, the first channel is connected to a microwave antenna integrated within the composite sensor chip via a microwave transmission line to generate a first tunable microwave field to drive electron spin resonance within the NV color center sensing layer. The ground-state spin level of the NV color center exhibits zero-field splitting at 2.87 GHz under zero magnetic field conditions, and undergoes Zeeman splitting under an applied bias magnetic field, with the splitting distance proportional to the magnetic field strength. The microwave field frequency output by the first channel is tunable around 2.87 GHz. When the microwave frequency matches the resonance frequency between specific spin sublevels of the NV color center, it induces electron spin transitions from the ground state to the excited state, leading to a change in NV fluorescence intensity—a phenomenon known as photodetector magnetic resonance. By scanning the microwave frequency and recording the changes in fluorescence intensity, ODMR spectral lines can be obtained, from which the resonance frequency can be extracted and the local magnetic field magnitude deduced. Integrating the microwave antenna within the chip allows the microwave field to directly act on the NV color center array, avoiding problems such as microwave field attenuation and inhomogeneity caused by the distance of an external microwave source.

[0107] The second channel connects to the three-dimensional coil group 9 and is used to generate an adjustable radio frequency or a second adjustable microwave field to modulate the atomic spins within the MEMS atomic cell layer. The MEMS atomic cell layer and the alkali metal atoms within it constitute the core sensing unit of the atomic magnetometer in SERF operation. By applying periodic modulation to the atomic spins, the magnetic field information to be measured can be transferred to the sideband of the modulation frequency. Subsequent lock-in amplification and demodulation effectively suppress low-frequency noise and environmental interference. The second channel connects to the three-dimensional coil group, utilizing existing coils to apply the modulation field, eliminating the need for additional dedicated modulation coils and simplifying the device structure. Alternatively, an independent radio frequency coil can be connected according to design requirements to obtain a purer modulation field distribution.

[0108] The magnetic shielding cylinder is placed outside the three-dimensional coil assembly to attenuate environmental interference magnetic fields. It utilizes the magnetic field focusing and bypassing effect of high magnetic permeability materials to absorb and guide external environmental magnetic fields, such as the geomagnetic field, power grid interference, and leakage magnetic fields from nearby equipment, around the internal space, thereby providing static magnetic shielding and low-frequency magnetic field attenuation for the internal area.

[0109] In some further embodiments, the tunable radio frequency or second tunable microwave field output by the second channel covers a frequency range from kHz to GHz, and the appropriate modulation frequency can be selected according to the specific requirements of atomic spin modulation. Modulation in the low-frequency kHz range is suitable for low-frequency noise suppression of the magnetic field, while modulation in the high-frequency MHz range is suitable for resonant driving of atomic spins.

[0110] In some further embodiments, the magnetic shielding cylinder is made of a high-permeability material and is cylindrical or has a multi-layered nested structure, enclosing the entire three-dimensional coil assembly and composite sensing chip. The shielding effectiveness of the magnetic shielding cylinder is typically measured by the shielding factor, which is the ratio of the external magnetic field to the internal residual magnetic field. Through the multi-layered shielding structure design, the internal residual magnetic field can be reduced to the nT or even pT level, providing excellent initial conditions for the fine compensation of the three-dimensional coil assembly and significantly reducing the compensation burden on the coil assembly.

[0111] In some further embodiments, the microwave antenna is disposed adjacent to the NV color center sensing layer, specifically located at the bottom layer of the composite sensing chip or embedded in the spaced coupling layer, in order to minimize the coupling distance between the microwave field and the NV color center array and improve microwave excitation efficiency.

[0112] In some further embodiments, the magnetic field subsystem works in conjunction with integrated functional elements. Correspondingly, the integrated functional elements also include a high-precision magnetic compensation module, configured as a micro-coil array embedded in the spaced coupling layer or disposed around the MEMS atomic gas cell layer, for performing localized fine compensation of the residual magnetic field in the region where the composite sensing chip is located.

[0113] In some of these embodiments, please continue to refer to Figure 1 and Figure 2 The processing system also includes a signal processing subsystem 6. Specifically, the signal processing subsystem 6 is used to perform a rapid wide-field magnetic scan of the sample under test based on the magnetic response optical signal generated by the MEMS atomic gas cell layer 4 to identify the region of interest; the signal processing subsystem is also used to spatially guide the scanning imaging area of ​​the NV color center sensing layer 2 based on the identification result of the region of interest to determine the scanning area of ​​the NV color center sensing layer 2.

[0114] Specifically, the atomic magnetometer composed of MEMS atomic gas chambers possesses femtotes-level sensitivity, enabling rapid scanning of a large sample area within a short time to obtain the overall magnetic field distribution of the sample; however, its spatial resolution is limited by the size of the gas chambers, making it unable to distinguish fine structures. The signal processing subsystem analyzes the scan data to identify regions of magnetic field anomalies or drastic changes as regions of interest, providing spatial guidance for subsequent high-resolution scanning.

[0115] The signal processing subsystem is also used to spatially guide the scanning imaging area of ​​the NV color center sensing layer based on the region of interest identification results, so as to determine the scanning area of ​​the NV color center sensing layer.

[0116] Specifically, by limiting the high-resolution scanning of the NV color center to the region of interest, time-consuming high-density point-by-point scanning across the entire field is avoided, significantly improving imaging efficiency.

[0117] The signal processing subsystem is also used to generate control commands within the scanning area to traverse and excite the scanning points of the NV color center sensing layer, and simultaneously acquire the NV fluorescence signal generated at each scanning point and the magneto-response optical signal generated at the location of the MEMS atomic gas cell layer corresponding to each scanning point.

[0118] Synchronous acquisition ensures that the two types of signals originate from the same spatial location and the same sample state at the same time, providing a spatiotemporal consistency basis for subsequent joint processing.

[0119] The signal processing subsystem is also used to perform real-time in-situ calibration of the relative magnetic field change measured by the NV fluorescence signal based on the absolute magnetic field value measured by the magneto-response optical signal, establish a calibration model, and perform calibration on the relative magnetic field change based on the calibration model.

[0120] Specifically, the magneto-optical signal output by the MEMS atomic magnetometer can be traced back to the absolute magnetic field strength after calibration, while the frequency shift of the ODMR spectrum measured by the NV color center only reflects the relative change in the magnetic field. By simultaneously acquiring both types of signals at the same location and establishing a mapping relationship between the absolute magnetic field value and the relative change, the high-resolution relative measurement results of the NV color center can be converted into a quantitative magnetic field value with absolute accuracy, solving the problem that the NV color center cannot directly output the absolute magnetic field.

[0121] In some further embodiments, the signal processing subsystem is also used to establish a physical forward model describing the composite sensing chip. The physical forward model includes the Green's function of the NV color center sensing layer, the weighting function of the MEMS atomic gas cell layer, and the magnetic flux coupling relationship between the NV color center sensing layer and the MEMS atomic gas cell layer through the spacer coupling layer.

[0122] Specifically, the Green's function describes the response characteristics of the NV color center sensing layer as a point sensor to magnetic sources at various points in space, the weighting function describes the weighted average response of the MEMS atomic gas chamber layer as a volume sensor to magnetic sources at various points in space, and the magnetic flux coupling relationship characterizes the attenuation and distortion of the sample's magnetic signal during its transmission from the NV color center sensing layer to the MEMS atomic gas chamber layer. This physical forward model fully expresses the mathematical mapping relationship from the sample's magnetic moment distribution to the two types of measurement signals.

[0123] The signal processing subsystem is also used to perform collaborative inversion of synchronously acquired NV fluorescence signals and magneto-response optical signals based on a physical forward model, calculate the magnetic moment distribution of the sample under test, and generate a fused magnetic image based on the magnetic moment distribution.

[0124] The aforementioned collaborative inversion specifically refers to using two types of measurement signals as constraints, and finding the magnetic moment distribution that optimally matches both types of measurements by solving the inverse problem of the physical forward model. The NV signal provides high spatial resolution constraints, while the MEMS signal provides high sensitivity constraints. The two complement and verify each other during the inversion process. The final calculated magnetic moment distribution retains the fine structure of the NV signal and possesses the high signal-to-noise ratio of the MEMS signal. The generated fused magnetic image outperforms the single sensing mode in both spatial resolution and sensitivity.

[0125] In some further embodiments, the signal processing subsystem is also used to perform system initialization before scanning imaging. Specifically, the signal processing subsystem controls the magnetic field subsystem to perform system-level demagnetization on the area where the composite sensor chip is located, eliminating any residual magnetism that may be carried by the chip and surrounding structures; subsequently, based on the magneto-response optical signal generated by the MEMS atomic gas cell layer itself or the feedback signal from its built-in magnetic field sensor, the static magnetic field of the imaging area is finely calibrated and compensated until the MEMS atomic gas cell layer stabilizes in the near-zero magnetic field environment required for SERF operation.

[0126] In some further embodiments, the signal processing subsystem is also used to generate a synchronization control timing sequence, ensuring that the point-by-point scanning excitation of the NV color center sensing layer is strictly synchronized in time with the acquisition of the magneto-optical signal from the MEMS atomic cell layer. Since the response speed of the MEMS atomic cell layer is limited by the atomic spin relaxation time, its output magneto-optical signal exhibits a certain delay and broadening. The signal processing subsystem measures the impulse response function of the MEMS atomic cell layer through pre-experimentation and performs deconvolution processing on the acquired magneto-optical signal to recover the instantaneous magnetic field value corresponding to the scanning point time of the NV color center, thus achieving precise registration of the two types of signals in the time dimension.

[0127] In further embodiments, the signal processing subsystem is also used to establish a magnetic flux coupling correlation model between the NV fluorescence signal and the magnetoresistive optical signal. This correlation model, based on physical parameters such as the thickness and permeability of the spacer coupling layer, describes the attenuation coefficient and phase delay of the near-field magnetic signal as it propagates from the NV color center sensing layer to the MEMS atomic gas cell layer. Using this correlation model, the signal processing subsystem performs spatial registration and amplitude matching on the synchronously acquired NV fluorescence signal and magnetoresistive optical signal, enabling joint analysis of the magnetic field information carried by the two types of signals within a unified physical coordinate system.

[0128] In further embodiments, the signal processing subsystem is also used to establish a spatial weighting function for the MEMS atomic gas chamber layer. This weighting function describes the contribution weight of atoms at different spatial locations within the MEMS atomic gas chamber layer to the magneto-optical signal, and depends on the density distribution of alkali metal atoms within the gas chamber, the pump light intensity distribution, and the geometry of the gas chamber. Based on this weighting function, the signal processing subsystem performs spatial weighted integration on the local magnetic field distribution measured by the NV color center sensing layer to obtain the predicted magneto-optical signal. The predicted signal is then compared with the actually acquired magneto-optical signal, and high-precision inversion of the sample's magnetic moment distribution is achieved through iterative optimization.

[0129] In some further embodiments, the device also includes an active noise suppression module connected to the signal processing subsystem. This module uses the noise spectrum of the magneto-response optical signal output as a reference signal, which mainly includes ambient magnetic field interference and the background noise of the atomic magnetometer itself. The active noise suppression module uses an adaptive filtering algorithm to identify and cancel common-mode noise components associated with the reference signal from the NV fluorescence signal, thereby significantly improving the signal-to-noise ratio of the NV measurement channel in the low-frequency range, enabling the NV color center sensing layer to achieve higher sensitivity magnetic field measurements in the originally noise-dominated low-frequency region.

[0130] It should be noted that the above-mentioned modules can be functional modules or program modules, and can be implemented by software or hardware. For modules implemented by hardware, the above-mentioned modules can reside in the same processor; or the above-mentioned modules can reside in different processors in any combination. The terms "module," "unit," "subunit," etc., used above can refer to combinations of software and / or hardware that implement a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0131] This embodiment provides a multimodal magnetic imaging method based on the fusion of NV color centers and MEMS atomic gas cell layers. Figure 4 This is a flowchart of the multimodal magnetic imaging method based on the fusion of NV color centers and MEMS atomic gas cell layers provided in this embodiment. Please refer to it. Figure 4 The process includes the following steps:

[0132] Step S410: A composite sensing chip, which integrates an NV color center sensing layer, a spacer coupling layer, and a MEMS atomic gas cell layer from bottom to top, is used to scan the sample under test.

[0133] Step S420: Obtain the NV fluorescence signal generated by the NV color center sensing layer in the composite sensing chip, and obtain the magneto-response optical signal generated by the MEMS atomic gas cell layer in the composite sensing chip.

[0134] Step S430: Generate a fused magnetic image based on the NV fluorescence signal and the magnetic response optical signal.

[0135] This method is used to implement the above embodiments and preferred embodiments, and will not be repeated hereafter.

[0136] In some of these embodiments, Figure 5 This is a flowchart illustrating the multimodal magnetic imaging method based on the fusion of NV color centers and MEMS atomic gas cell layers provided in this embodiment. Please refer to it. Figure 5 In conjunction with the aforementioned embodiments and their preferred embodiments, the multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers, the specific execution flow of the method in this embodiment includes the following steps:

[0137] In a multi-layered magnetically shielded environment, a system-level demagnetization operation is performed on the device to eliminate residual magnetic fields. Subsequently, using a high-precision magnetometer and the magnetic response optical signal feedback from the MEMS atomic gas cell layer itself, the static magnetic field of the entire imaging area is precisely calibrated and compensated, stabilizing the MEMS atomic gas cell layer in the near-zero magnetic field environment required for SERF operation.

[0138] Within the first time interval, preferably between 1 and 10 seconds, the second laser is activated, and a rapid wide-field magnetic scan of the sample is performed using an atomic magnetometer composed of MEMS atomic gas chambers. By analyzing the scan data, regions of magnetic anomalousness or regions of interest in the sample are identified, and the scan points are determined.

[0139] In the second time interval, preferably within 10 milliseconds to 1 second, the first laser is turned on, and the first wavelength laser is focused onto the determined scanning point through the objective lens to selectively excite the NV color center sensing layer and perform high-resolution scanning on the scanning point.

[0140] During high-resolution scanning, the magnetic field subsystem is activated. A precise bias magnetic field is provided for NV color center measurement via a three-dimensional coil array, while a frequency-tunable microwave field is applied through the first channel of a programmable microwave source to drive the electron spin resonance of the NV color centers.

[0141] Simultaneously with excitation and stimulation, the NV fluorescence signal collected by the objective lens at the current scanning point and the magnetic response optical signal carrying atomic magnetic response information are simultaneously acquired through the common detection optical path of the optical subsystem.

[0142] Using the absolute magnetic field value measured by the magneto-response optical signal as a reference, a calibration model is established through the signal processing subsystem to perform real-time in-situ calibration and absolute calibration of the relative magnetic field change measured by the NV fluorescence signal, thereby realizing the quantification of the measurement results.

[0143] Based on the physical forward model describing the composite sensing chip, the synchronously acquired NV fluorescence signal and magnetoresistive optical signal are input to the signal processing subsystem. By executing a collaborative inversion algorithm, the optimal sample magnetic moment distribution is jointly calculated from the two types of signals, generating a fused magnetic image with a signal-to-noise ratio and spatial resolution superior to that of a single sensing mode.

[0144] The scanning galvanometer is controlled or the optical focus is moved to scan point by point along the guided path. The aforementioned steps are repeated until the entire target area is covered. Finally, the signal processing subsystem integrates the calculation results of all scan points to generate and output a final magnetic imaging result with high sensitivity, high spatial resolution, and high quantitative accuracy.

[0145] The first and second time intervals in the above steps can be dynamically adjusted according to the characteristics of the sample to be tested and the imaging requirements. For example, a shorter first time interval can be used for rapid scanning during preliminary screening, while a longer second time interval can be used for fine imaging to improve the signal-to-noise ratio.

[0146] This embodiment also provides a computer device, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0147] Optionally, the computer device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0148] Furthermore, in conjunction with the multimodal magnetic imaging method based on the fusion of NV color centers and MEMS atomic gas cell layers provided in the above embodiments, this embodiment can also provide a storage medium for implementation. This storage medium stores a computer program; when executed by a processor, the computer program implements any of the multimodal magnetic imaging methods based on the fusion of NV color centers and MEMS atomic gas cell layers described in the above embodiments.

[0149] It should be noted that all information and data involved in this application are authorized by the user or fully authorized by all parties and will be used legally.

[0150] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0151] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

[0152] The term "embodiment" in this application refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply that it is mutually exclusive with or independent of other embodiments. It will be clearly or implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0153] The above embodiments merely illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application.

Claims

1. A multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers, characterized in that, include: The composite sensor chip integrates, from bottom to top, an NV color center sensing layer, a spacer coupling layer, and a MEMS atomic gas cell layer. The NV color center sensing layer is used to detect the near-field magnetic signal generated by the sample under excitation state in order to generate NV fluorescence signal; The spacer coupling layer is used to isolate the NV color center sensing layer and the MEMS atomic gas cell layer, couple the near-field magnetic signal into a coupled magnetic signal, and conduct it to the MEMS atomic gas cell layer. The MEMS atomic gas cell layer is used to detect the coupled magnetic signal in the SERF operating state in order to generate a magneto-response optical signal; The processing system operates on the composite sensor chip to put the NV color center sensing layer into the excited state, to put the MEMS atomic gas cell layer into the SERF working state, and to generate a fused magnetic image based on the NV fluorescence signal and the magneto-response optical signal.

2. The multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers according to claim 1, characterized in that, The first surface of the NV color center sensing layer is in contact with the second surface of the spaced coupling layer; The NV color center sensing layer has an NV color center array; the distance between the NV color center array and the first surface of the NV color center sensing layer is less than a first preset threshold. The spacer coupling layer is an insulating thermally conductive medium; The MEMS atomic gas chamber layer is a sealed cavity, and an alkali metal atom source and a buffer gas are provided inside the MEMS atomic gas chamber layer.

3. The multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers according to claim 2, characterized in that, The distance between the NV color center array and the first surface of the NV color center sensing layer is less than 100 nm; The spacer coupling layer is made of silicon nitride or silicon dioxide and has a thickness of 50 nm to 10 μm. The cavity planar dimensions of the MEMS atomic gas chamber layer range from 10 μm to 500 μm, and the height ranges from 1 μm to 50 μm. The alkali metal atom source includes rubidium or potassium, and the buffer gas includes nitrogen or helium with a pressure range of 10 Torr to 1000 Torr.

4. The multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers according to claim 2, characterized in that, The composite sensing chip also includes: Integrated functional elements, disposed around the MEMS atomic gas chamber layer or embedded in the spaced coupling layer, are used to monitor and regulate the temperature of the MEMS atomic gas chamber layer and to apply a microwave field to the NV color center sensing layer.

5. The multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers according to claim 1, characterized in that, The processing system includes an optical subsystem; the optical subsystem includes: A first laser is used to output a first wavelength laser, so that the first wavelength laser is incident on the NV color center sensing layer, so that the NV color center array in the NV color center sensing layer is in the excited state. The second laser is used to output a second wavelength laser, which runs sequentially along the NV color center sensing layer and the spaced coupling layer, and is incident on the MEMS atomic gas cell layer to pump and probe the alkali metal atoms in the MEMS atomic gas cell layer, so that the MEMS atomic gas cell layer is in the SERF working state. The spectrophotometer module is located near one end of the MEMS atomic gas cell layer. It is used to receive the mixed optical signal, separate the mixed optical signal into the NV fluorescence signal and the magnetic response optical signal, and guide them to the corresponding photodetectors respectively.

6. The multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers according to claim 1, characterized in that, The processing system includes a magnetic field subsystem; the magnetic field subsystem includes: A three-dimensional coil array is arranged around the composite sensing chip to apply a compensation magnetic field to the composite sensing chip, to apply a near-zero magnetic field to the MEMS atomic gas cell layer, and to apply an adjustable bias magnetic field to the NV color center sensing layer. This allows the NV fluorescence signal generated by the NV color center sensing layer to carry the local magnetic field information of the sample under test, and the magnetoresistive optical signal generated by the MEMS atomic gas cell layer to carry the overall magnetic flux information of the sample under test.

7. The multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers according to claim 6, characterized in that, The magnetic field subsystem also includes: A programmable microwave source, comprising at least an independent first channel and a second channel; The first channel is connected to a microwave antenna integrated in the composite sensor chip via a microwave transmission line to generate a first tunable microwave field to drive electron spin resonance in the NV color center sensing layer. The second channel, connected to the three-dimensional coil group, is used to generate an adjustable radio frequency or a second adjustable microwave field to modulate the atomic spins within the MEMS atomic gas chamber layer; A magnetic shielding cylinder is placed outside the three-dimensional coil group to attenuate the environmental interference magnetic field.

8. The multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers according to any one of claims 1 to 7, characterized in that, The processing system also includes a signal processing subsystem; The signal processing subsystem is used to perform magnetic scanning on the sample under test based on the magnetic response optical signal generated by the MEMS atomic gas cell layer to identify the region of interest; the signal processing subsystem is also used to spatially guide the scanning imaging area of ​​the NV color center sensing layer based on the identification result of the region of interest to determine the scanning area of ​​the NV color center sensing layer. The signal processing subsystem is also used to generate control commands within the scanning area to perform traversal scanning excitation of the scanning points of the NV color center sensing layer, and to simultaneously acquire the NV fluorescence signal generated at each scanning point and the magneto-response optical signal generated at the location of the MEMS atomic gas cell layer corresponding to each scanning point. The signal processing subsystem is also used to perform real-time in-situ calibration of the relative magnetic field change measured by the NV fluorescence signal based on the absolute magnetic field value measured by the magneto-response optical signal, establish a calibration model, and perform calibration on the relative magnetic field change based on the calibration model.

9. The multimodal magnetic imaging device based on the fusion of NV color centers and MEMS atomic gas cell layers according to claim 8, characterized in that, The signal processing subsystem is also used to establish a physical forward model describing the composite sensing chip. The physical forward model includes the Green's function of the NV color center sensing layer, the weighting function of the MEMS atomic air cell layer, and the magnetic flux coupling relationship between the NV color center sensing layer and the MEMS atomic air cell layer through the spacer coupling layer. The signal processing subsystem is also used to perform a collaborative inversion of the synchronously acquired NV fluorescence signal and magnetic response optical signal based on the physical forward model, calculate the magnetic moment distribution of the sample under test, and generate the fused magnetic image based on the magnetic moment distribution.

10. A multimodal magnetic imaging method based on the fusion of NV color centers and MEMS atomic gas cell layers, characterized in that, include: A composite sensing chip, which integrates an NV color center sensing layer, a spacer coupling layer, and a MEMS atomic gas cell layer from bottom to top, was used to scan the sample under test. The NV fluorescence signal generated by the NV color center sensing layer in the composite sensing chip is obtained, and the magneto-response optical signal generated by the MEMS atomic gas cell layer in the composite sensing chip is obtained. A fused magnetic image is generated based on the NV fluorescence signal and the magneto-response optical signal.

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